refactor: remove legacy HeroSection component (orphaned code)

BREAKING: Remove unused HeroSectionRenderer and content-hero template

Analysis confirmed HeroSection was legacy orphaned code:
- No JSON schema (hero-section.json didn't exist)
- No FormBuilder for admin UI
- No database records (component_name='hero-section')
- No template usage (single.php uses 'hero' not 'hero-section')
- Violated Clean Architecture (hardcoded CSS)

Removed files:
- Public/HeroSection/Infrastructure/Ui/HeroSectionRenderer.php
- TemplateParts/content-hero.php
- case 'hero-section' from functions-addon.php switch

Active Hero component (Schemas/hero.json + HeroRenderer.php) remains unchanged.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

TemplateParts/content-hero.php

@@ -1,61 +0,0 @@
-<?php
-/**
- * Hero Section Template
- *
- * Hero section con degradado azul para single posts
- *
- * @package ROI_Theme
- */
-
-if (!is_single()) {
-    return;
-}
-?>
-
-<section class="hero-section">
-    <div class="container-fluid py-5">
-        <div class="hero-content text-center">
-
-            <!-- Category Badges (ARRIBA del H1) -->
-            <?php
-            $categories = get_the_category();
-            if (!empty($categories)) :
-            ?>
-                <div class="hero-categories mb-3">
-                    <?php foreach ($categories as $category) : ?>
-                        <?php if ($category->name !== 'Uncategorized' && $category->name !== 'Sin categoría') : ?>
-                            <span class="hero-category-badge"><?php echo esc_html($category->name); ?></span>
-                        <?php endif; ?>
-                    <?php endforeach; ?>
-                </div>
-            <?php endif; ?>
-
-            <!-- H1 Title -->
-            <h1 class="hero-title"><?php the_title(); ?></h1>
-
-            <!-- Post Meta -->
-            <div class="hero-meta">
-                <span class="hero-meta-item">
-                    <i class="bi bi-calendar3 me-1"></i>
-                    <?php echo get_the_date(); ?>
-                </span>
-                <span class="hero-meta-separator">|</span>
-                <span class="hero-meta-item">
-                    <i class="bi bi-person me-1"></i>
-                    <?php the_author(); ?>
-                </span>
-                <?php
-                $reading_time = roi_get_reading_time();
-                if ($reading_time) :
-                ?>
-                    <span class="hero-meta-separator">|</span>
-                    <span class="hero-meta-item">
-                        <i class="bi bi-clock me-1"></i>
-                        <?php echo esc_html($reading_time); ?>
-                    </span>
-                <?php endif; ?>
-            </div>
-
-        </div>
-    </div>
-</section>